Rotary rock-drill.



'J. .B. STRAUSS &-, G. L. BROWN.

I ROTARY ROCK DRILL.

APPLICATION FILED JAN.31, 1912.

Patented Nov. .26, 1912.

2 SHEETS-SHEET 2 aoaarsa warren srarns Parana orrroa JULIAN B. SI RAUSSA ND CHARLES L. BROWN, 01 NEW ORLEANS, LOUISIANA.

ROTARY ROCK-DRILL.

Specification of Letters Patent.

Patented Nov. 26, 1912.

. T all whom it may conce rn:

r Be it known that we, JULIAN STRAUSS I and CHARLES L. BROWN, citizens of the United States, residing at New Orleans, in the parish of ()rleans and State of Louisiana, have invented certain new and useful Improvements in Rotary Rock-Drills; and we do hereby declare the following to be a full," clear, and exact'description of the in drilled hole and to out equally over all por-- tions of the base of said hole.

In the accompanying drawings, forming a part of this application, and in which similar reference symbols indicate corresponding parts in the several views ;Figure 1 is a side elevation, with the left-hand half in section on an axial plane of the drill, illustrating one' embodiment of our invention; Fig. 2 is a plan of the construction shown in Fig. 1, with the extreme lefthand frusto -conical cutter partially in section; Fig. 3 is a side elevation, partially in section, illustrating a modification; and Fig. 4 is a plan of the con struction shown in Fig. 3.

Referring to the drawings, 1 indicates the head of a rotary drill provided with threads 2 for attachment to a drill rod, or other suitable actuating member; said head being provided with fork arms 3 and 4 spaced at different distances from the axis of the drill.

A series of frusto-conical cutters 5, 6 and 7 are rotatably mounted on a spindle 8 rigidly mounted in the arms 3 and 4 perpendicularly to the axis of the drill; said spindle being shown threaded at 9 into the arm 4 and provided with an enlarged head 10 I abutting against the arm 3 to provide a jour-' nal for the cutter 7 and terminating in a radial flange 11 for confining said cutter in position.

The drill head is provided with passages 12 for the efiicient introduction of wash-out watertoward the center of the drilled hole,

tical conditions, it is advantageous to provide said bushings with rings of graphite, Babbitt metal, or other anti-friction material. Wear washers 16, 17, 18 and 19 are confined between said several cutters and the fork arms, and a similar washer 20,is shown between the cutter 7 and retaining flange 11.

As shown in the drawings, the several cutters comprise unequal frusta of equal, right, circular cones so arranged that the cutting diameters increase proportional to the distance from the axis of the drill; whereby said cutters are adapted to drill a hole having a conical base which tends to automatically maintain the-drill centered.

-The frusto-conical cutters 5 and 6 are pro-' vided peripherally with annular series of pyramidal teeth which are arranged asymmetrically to the axisv of the drill on said respective cutters; whereby the teeth of each cutter will track between those of the other and out clear spaces for the non-cutting portions of the latter. The outer cutter 7 is provided with similar series of cutting teeth arranged spirally thereon, for working the broken material toward the center of the drilled hole in advantageous position for removal by the wash-out water introduced through the passages 12. If desired, the pyramidal teeth on the cutters 5 and 6 may also be arranged spirally for working all of the material toward the center of the drilled. hole. 1

Figs. 3 and 4 illustrate a modification in which the drill head 21 is provided witlra threaded portion 22 for attachment to a drill rod, and with fork arms 23 and 24:

spaced unequally from the axis of the drill.

A spindle 25 is rigidly secured in said arms, as by a threaded portion 26, and rotatably supports two frusto-conical cutters 27 and 28 similar to thosev previously described; said spindle being provided with an enlargement 29 engaging the arm 24 to provide a journal for the cutter 28 and terminating in a radial flange 30 for confining said cutter in position.

We claim 1.- In a drill, the combination of-a drill head provided with fork arms spaced at different dlstances on diametrically opposite sldes of the drill axis, a spindle mounted in said arms perpendicularly to the drill axis,

and a series of cutters mounted for independent rotation on said spindle and ex tending axially at different distances from the drill axis for tracking with said unequally spaced arms upon rotation of the drill head. v

2.- In a drill, the combination of a drill head provided with fork arms spaced at different distanceson diametrically opposite sides of-the drill axis, a spindle mounted in said arms perpendicularly to the drill axis, and a series of cutters mounted for independent rotation on said spindle and provided peripherally with pyramidal teeth arranged asymmetrically to the drill axis on said several cutters, said several cutters extending axially at different distances from the drlll axis for tracking with said unsite sides of the drill axis, a spindle rigidly secured in one armand provided with an enlarged head abuttin v against the outer face of the other arm, rusto-conical cutters 4 mounted on said spindle and enlarged head and having diameters increasing at all points proportional to the distances of such points from the drill axis, and aradial flange on said enlarged head for confining said cutter thereon.

In testimony whereof, We afiix our signatures, in presence of two witnesses.

' JULIAN B. STRAUSS. CHARLES L. BROWN.

Witnesses: I Y

W. K. DE PAss,

F. C. BACKSTROM. 

